check out this listing for the steering wheel.

E53 OEM Sports Steering Wheel Facelift 4.8is 4.4i 3.0i : eBay Motors (item 290425001645 end time Apr-21-10 03:50:02 PDT)

for an additional $300 i will include a Brand New Facelift Sports Steering Wheel Air Bag, which is still in the original packaging and unopened.